i8o Field Columbian Museum — Zoology, Vol. VII. 



Along the greater part of the shore line the mountains rise perpen- 

 dicularly out of the water, and so within a few feet of the water's edge 

 the depth is very great. At almost any point along the shore from 

 San Lucas to Santa Cruz (the only shore where soundings were made 

 near the water's edge) the lake less than % mile from shore is between 

 400 and 700 feet in depth ; near the middle of the eastern half of the 

 lake its depth is over 1,000 feet. The deepest place found by me was 

 1,055 f^^t, which is probably the deepest place in the lake. 



The water in the lake is exceedingly clear. A white disc 1 2 inches 

 in diameter can easily be seen at a depth of 45 feet. The shallow 

 water near the shore is confined to the small stretches at the mouth 

 of the few small inlets, and to the shore to the north of Atitlan and 

 west of San Lucas. The margins of these areas usually support a 

 growth of Tules such as are found in Lake Amatitlan. In these 

 limited areas, water plants, as Chara, Potamogeton, and Algce, are 

 abundant. 



Of microscopical animal and plant life there is less to a cubic foot 

 of water in Lake Atitlan than in Amatitlan. As compared with its 

 immense volume of water the shore vegetation is very small and 

 the spawning and feeding grounds for fishes are very much re- 

 duced. 



The temperature of the water in Atitlan is 68 degrees. The surface 

 during warm days becomes slightly warmer to a depth of about 5 feet. 

 Below 5 or 10 feet the temperature of the water in the lake is 68° F. 

 I was unable to take the temperature deeper than 750 feet, but wher- 

 ever taken the temperature was the same. There are two small 

 streams flowing into the lake near Panajachel. Between 3 130 and 

 5:30 P.M. on February 19, the temperature of the water in both of 

 these streams near the lake was 64° F. 



In Lake Atitlan there are but three species of fishes, all of which 

 are natives of Lake Amatitlan. The largest is the Serica {Cichlasoma 

 nigrojasciatum) ; the most abundant is the Pescadito {Poecilia 

 sphenops), and by far the least important is the Gulumina (Fundulus 

 guatemalensis) . These fishes are much used for food by the natives, 

 especially by those people living in Santa Catalina. These fishes are 

 eaten only because no others are to be had. An effort is being made 

 to introduce into this lake fishes from the rivers of the lowland. 

 Already two or three species of Mojarra and. the Pepemechin have 

 been brought up from the lowlands and placed in a pond near San 

 Lucas. It is very doubtful if much benefit will be derived from this 

 effort to stock the lake, but certainly no harm can result from it. 

 The same energy, more wisely applied, might result in more good. 



